Manufacture of films for photographic and other purposes.



` Manufacture of Films for Photographic and UNITED STATES PATENT OFFICE.

JOHN HENRY SMITH, OF ZURICH, SWITZERLAND.

MANUFACTURE OF FILMS FOR PHOTOGRAPHIC AND OTHER PURPOSES.

Specification of Letters Patent.

Patented May 5, 1908.

Application filed May 15, 1905. Serial No. 260,436.

To all whom it may concern:

Be it known thatl I, JOHN HENRY SMITH, a subject of the King of Great Britain, residing in'Zurich, in the canton of Zurich, Republic of Switzerland, (whose post-office address is No. 417 Seestrasse, Zurich,) have invented certain new and useful Improvements in the other Purposes; and I do hereby declare the following to be a full, clear, and exact description of the invention, such-as will enable others skilled in the art to which it apper tains to make and use the same, reference being hadl to the accompanying drawings, and to letters of reference marked thereon,

Awhich form a part of this specification.

The subject of the present invention is an improved rocess for the manufacture of films for p otographic and other purposes. According vto this process two component films are prepared by coating upon an apprelpriate smooth support a gelatin solution. an

Figure 1 of the drawings 1s a vertical sectionalview Vof a complete film constructed according to this invention. Fig. 2 is a vertical sectional view illustrating the manner of constructingone of the component films.

In the first instance, a temporary' smooth support for the film is made. For this purpose a solution of gelatin (d) is coated upon paper, glass, etc. (c in Fig. 2) and then dried. Afterwards a solution of nitro-cellulose'-A in ether-alcohol, methyl-alcohol or other solvent is coated upon the gelatin film and also dried. After drying, the residual film (e) of the nitro-cellulose solution forms a smooth surface for the suppxort of the component films, and this support may be repeatedly used for this purpose. Upon this support an aqueous solution of gelatin which may contain a small addition of glycerinand some hardening agent in order to obtain the necessary vpliability and solidity for the finished film 1s then coated asindicated at a, the thickness of the coating depending upon the desired thickness of the fnlshed film. A nitro-cellulose solution, as l), is then coated upon the gelatin surface a and the film then a l owed to dry. On account of the penetration of the nitro-cellulose solution (b) into the body of the gelatin (a) a very tenacious combination results. The intimately combined films (af) and (b) are then stripped from the nitro-cellulose coating (e) of the temporary sup )ort and form one of the component films. n the same Way the second component film a, b is produced. lAfterwards the exposed gelatin surfaces (a a) of both component films are brought together, moistened slightly and squeegeed together producing,

the finished film (Fig. l). These films can he prepared by machinery in rolls of any length and in a width of one meter or even more. This process might be simplified by doubling a single component film a ter stripping in the middle wlth the gelatin surface inside and squeegeeing the two halves toget 1er.

Formerly it was usual in order to obtain an eXtra thick gelatin film to coat the gelatin solution twice, whereas by this process a double thickness of film can be obtained with a single coating. 4

The squeegeeing of'` the two component films does not occupy in practice any eXtra time as it can be performed simultaneously with the cutting up of the finished film into sizes.

What I claim is:

1. A process for manufacturing a gelatin film for photogra hic and other urposes coated on both si es with the residue of a nitro-cellulose solution consisting in squeegeeing together into intimate contact two layers of gelatin which have been previously coated with a protecting layer of collodion.

2. The herem described rocess for the manufacture of a gelatin 11m forl photographic and other urposes, coated on both sides with the resi ue of' a nitro-cellulose solution consisting in the preparation of two component'I films lilyv coating anddrying upon In testimony whereof, I have signed a prepared temporary su port 1n .succession name to this specification in the presenceg' a gelatin and a mtro-cellu ose solution, striptwo subscribing' Witnesses. 'y

ping these component lms from their supvJOHN HENRY SMITH. 5 port, slightly moistening the exposed gelatlu Witnesses:

surfaces -and. bringing them into intimate HERMANN HUBER,

contact by squeegeeing together. JOSEPH SIMON. 

